Fix license for Planka (#3514)

README.md

@@ -1954,7 +1954,7 @@ _Related: [Software Development - Project Management](#software-development---pr
 - [myTinyTodo](https://www.mytinytodo.net/) - Simple way to manage your todo list in AJAX style. Uses PHP, jQuery, SQLite/MySQL. GTD compliant. ([Demo](https://www.mytinytodo.net/demo/), [Source Code](https://github.com/maxpozdeev/mytinytodo/)) `GPL-2.0` `PHP`
 - [Nullboard](https://github.com/apankrat/nullboard) - Single-page minimalist kanban board; compact, highly readable and quick to use. `BSD-2-Clause` `Javascript`
 - [Our Shopping List](https://github.com/nanawel/our-shopping-list) - Simple shared list application. Typical uses include shopping lists of course, and any other small todo-list that needs to be used collaboratively. ([Demo](https://osl.lanterne-rouge.info/)) `AGPL-3.0` `Docker`
-- [Planka](https://planka.app/) - Open source Trello alternative. ([Demo](https://plankanban.github.io/planka/#/), [Source Code](https://github.com/plankanban/planka)) `MIT` `Nodejs`
+- [Planka](https://planka.app/) - Open source Trello alternative. ([Demo](https://plankanban.github.io/planka/#/), [Source Code](https://github.com/plankanban/planka)) `AGPL-3.0` `Nodejs`
 - [Restyaboard](https://github.com/RestyaPlatform/board/) - Open source Trello-like kanban board. `OSL-3.0` `PHP`
 - [Task Keeper](https://github.com/nymanjens/piga) - List editor for power users, backed by a self-hosted server. `Apache-2.0` `Scala`
 - [TaskBoard](https://taskboard.matthewross.me/) - Kanban-inspired app for keeping track of things that need to get done. ([Demo](https://taskboard.matthewross.me/demo.html), [Source Code](https://github.com/kiswa/TaskBoard)) `MIT` `PHP`